Conventionally, a semiconductor device such as an integrated circuit (IC) or a large-scale integrated circuit (LSI) with a terminal of a pin grid array (PGA) type is connected to a circuit board such as a printed circuit board when an IC tester is used for testing. In such a case, the terminal of the semiconductor device is electrically connected to a conductive trace of the circuit board, via of a socket attached to the circuit board (for example, refer to Patent Document 1).
FIG. 11 is a cross-sectional view of main parts of a conventional socket.
In the drawing, 811 denotes a housing of the socket used for connecting the semiconductor device to the circuit board. The housing is a plate shaped member made of an insulating material such as resin, and has a plurality of terminal accommodating chambers 813 formed therein. Adjacent terminal accommodating chambers 813 are partitioned from one another by an inclined wall 814.
Each terminal accommodating chamber 813 accommodates a terminal 861. The terminal 861 includes an arcuate part 863, a first arm 864 extending diagonally upward from the arcuate part 863, and a second arm 862 extending diagonally downward from the arcuate part 863. A first contact part 864a protruding upward beyond an upper surface of the housing 811 is formed at the upper end of the first arm 864. A second contact part 862a protruding downward beyond a lower surface of the housing 811 is formed at the lower end of the second arm 862. The arcuate part 863 is positioned within a step 815 formed in a lower portion of the inclined wall 814.
When the socket is used to connect the semiconductor device to the circuit board, the first contact part 864a is pressed by a terminal exposed on a lower surface of an unillustrated semiconductor device from above, and the second contact part 862a is pressed by a terminal exposed on an upper surface of an unillustrated circuit board from below. When the first contact part 864a is pressed from above, the first arm 864 elastically deforms in a clockwise direction about the arcuate part 863, whereby the first contact part 864a is elastically displaced obliquely downward to the right. When the second contact part 862a is pressed from below, the second arm 862 elastically deforms in a counterclockwise direction about the arcuate part 863, whereby the second contact part 862a is elastically displaced obliquely upward to the right. Thus, the first contact part 864a and the second contact part 862a ensure a contact state to be maintained between the semiconductor device and the terminal of the circuit board.    Patent Document 1: Japanese Patent Publication No. 2015-133332